Elmicro Computer / FM25W256

Device Driver for RAMTRON FM25W256 SPI-driven FRAM Uses SPI peripheral at 10MHz Based on fast SPI routines

Dependents:   RAMTRON_FM25W256

fm25w256.cpp@0:2290931492e7, 2012-04-05 (annotated)

Committer:
elmicro
Date:
Thu Apr 05 10:15:52 2012 +0000
Revision:
0:2290931492e7
Initial Revision with Read Block, Write Block, Read Byte, Write Byte

Who changed what in which revision?

UserRevisionLine numberNew contents of line
elmicro 0:2290931492e7 1 #include "fm25w256.h"
elmicro 0:2290931492e7 2 #include "mbed.h"
elmicro 0:2290931492e7 3
elmicro 0:2290931492e7 4 /* ===================================================================
elmicro 0:2290931492e7 5 routine: FM25W_SSP1_Init
elmicro 0:2290931492e7 6 purpose: Configures the LPC1768's SSP1 peripheral for
elmicro 0:2290931492e7 7 communication with Ramtron FM25W256 FRAM memory
elmicro 0:2290931492e7 8 parameters: none
elmicro 0:2290931492e7 9 returns: nothing
elmicro 0:2290931492e7 10 date: 2012-04-05
elmicro 0:2290931492e7 11 author: Stefan Guenther
elmicro 0:2290931492e7 12
elmicro 0:2290931492e7 13 * hardware connection scheme: *
elmicro 0:2290931492e7 14
elmicro 0:2290931492e7 15 mbed FRAM
elmicro 0:2290931492e7 16 (LPC1768)
elmicro 0:2290931492e7 17 --------+ +---------
elmicro 0:2290931492e7 18 | +Vcc _____ |
elmicro 0:2290931492e7 19 | o +-----| 4k7 |---------+ !WP
elmicro 0:2290931492e7 20 | | | |
elmicro 0:2290931492e7 21 VCC +------+------+ |
elmicro 0:2290931492e7 22 | | _____ |
elmicro 0:2290931492e7 23 | +-----| 4k7 |-------- + !HOLD
elmicro 0:2290931492e7 24 | <CLK> |
elmicro 0:2290931492e7 25 P0.7 +--->--------------------------->---+ SCK
elmicro 0:2290931492e7 26 | <MISO> |
elmicro 0:2290931492e7 27 P0.8 +---<---------------------------<---+ SO
elmicro 0:2290931492e7 28 | <MOSI> |
elmicro 0:2290931492e7 29 P0.9 +--->--------------------------->---+ SI
elmicro 0:2290931492e7 30 | <!SSL> |
elmicro 0:2290931492e7 31 P0.6 +--->--------------------------->---+ !CS
elmicro 0:2290931492e7 32 | |
elmicro 0:2290931492e7 33 GND +------------------+----------------+ GND
elmicro 0:2290931492e7 34 | | |
elmicro 0:2290931492e7 35 --------+ o +---------
elmicro 0:2290931492e7 36 0V
elmicro 0:2290931492e7 37 Keep traces as short as possible - SPI frequency is 10MHz!
elmicro 0:2290931492e7 38 -------------------------------------------------------------------*/
elmicro 0:2290931492e7 39 void FM25W_SSP1_Init(void)
elmicro 0:2290931492e7 40 {
elmicro 0:2290931492e7 41 LPC_SC->PCLKSEL0|=(1<<20); //SSP clock = 1x System Clock
elmicro 0:2290931492e7 42 LPC_SC->PCONP |= BIT10; //enable power to SSP1 peripheral
elmicro 0:2290931492e7 43 //P0.6 -> SSEL
elmicro 0:2290931492e7 44 //P0.7 -> SCK
elmicro 0:2290931492e7 45 //P0.8 -> MISO
elmicro 0:2290931492e7 46 //P0.9 -> MOSI
elmicro 0:2290931492e7 47 LPC_PINCON->PINSEL0 &=~0xFC000; //reset GPIO functions for needed portpins
elmicro 0:2290931492e7 48 LPC_PINCON->PINSEL0 |= 0xA8000; //set GPIO functions to SSP1
elmicro 0:2290931492e7 49 LPC_SSP1->CPSR=11; //SSP clock divider (results in 10MHz SPI Clk)
elmicro 0:2290931492e7 50 LPC_SSP1->CR0=7;//|0x80|0x40; //FRF=SPI, DSS=8, SPO=1, SPH=1
elmicro 0:2290931492e7 51 LPC_SSP1->CR1 &=~BIT2; //SSP1 is master
elmicro 0:2290931492e7 52 LPC_SSP1->CR1 |= BIT1; //enable SSP1 peripheral (SSE bit)
elmicro 0:2290931492e7 53 LPC_PINCON->PINSEL0 &=~0x3000; //p8 [P0.6] is Slave Select (software driven)
elmicro 0:2290931492e7 54 LPC_GPIO0->FIODIR |= BIT6; //P0.6 is output
elmicro 0:2290931492e7 55 SSL1;
elmicro 0:2290931492e7 56 }
elmicro 0:2290931492e7 57
elmicro 0:2290931492e7 58
elmicro 0:2290931492e7 59 /* ===================================================================
elmicro 0:2290931492e7 60 routine: FM25W_ReadByte
elmicro 0:2290931492e7 61 purpose: Reads a single byte from specified memory address
elmicro 0:2290931492e7 62 parameters: <iAddress> Memory address to read
elmicro 0:2290931492e7 63 returns: Memory content
elmicro 0:2290931492e7 64 date: 2012-04-05
elmicro 0:2290931492e7 65 author: Stefan Guenther
elmicro 0:2290931492e7 66 -------------------------------------------------------------------*/
elmicro 0:2290931492e7 67 unsigned char FM25W_ReadByte(unsigned int iAddress)
elmicro 0:2290931492e7 68 {
elmicro 0:2290931492e7 69 unsigned char retVal=0;
elmicro 0:2290931492e7 70 while(!(LPC_SSP1->SR&BIT0)); //wait for TX FIFO to get empty
elmicro 0:2290931492e7 71 SSL0;
elmicro 0:2290931492e7 72 LPC_SSP1->DR = READ;
elmicro 0:2290931492e7 73 LPC_SSP1->DR = (iAddress >> 8) & 0xFF; //Send top address byte to read from
elmicro 0:2290931492e7 74 LPC_SSP1->DR = iAddress & 0xFF; //Send Middle address byte to read from
elmicro 0:2290931492e7 75 LPC_SSP1->DR = 0;
elmicro 0:2290931492e7 76 while(LPC_SSP1->SR&BIT4); //wait for TX to end
elmicro 0:2290931492e7 77 while(LPC_SSP1->SR&BIT2) //read out RX FIFO
elmicro 0:2290931492e7 78 retVal = LPC_SSP1->DR; //last FIFO entry is our data byte
elmicro 0:2290931492e7 79 SSL1;
elmicro 0:2290931492e7 80 return(retVal);
elmicro 0:2290931492e7 81 }
elmicro 0:2290931492e7 82
elmicro 0:2290931492e7 83 /* ===================================================================
elmicro 0:2290931492e7 84 routine: FM25W_WriteByte
elmicro 0:2290931492e7 85 purpose: Writes a single byte to specified memory address
elmicro 0:2290931492e7 86 parameters: <iAddress> Memory address to write to
elmicro 0:2290931492e7 87 <cByte> Data to be written
elmicro 0:2290931492e7 88 returns: nothing
elmicro 0:2290931492e7 89 date: 2012-04-05
elmicro 0:2290931492e7 90 author: Stefan Guenther
elmicro 0:2290931492e7 91 -------------------------------------------------------------------*/
elmicro 0:2290931492e7 92 void FM25W_WriteByte(unsigned int iAddress, unsigned char cByte)
elmicro 0:2290931492e7 93 {
elmicro 0:2290931492e7 94 while(!(LPC_SSP1->SR&BIT0)); //wait for TX FIFO to get empty
elmicro 0:2290931492e7 95 SSL0;
elmicro 0:2290931492e7 96 LPC_SSP1->DR = WREN; //WREN has to be written prior to
elmicro 0:2290931492e7 97 //each write access to FRAM
elmicro 0:2290931492e7 98 while(LPC_SSP1->SR&BIT4); //wait for TX to end
elmicro 0:2290931492e7 99 SSL1;
elmicro 0:2290931492e7 100 while(LPC_SSP1->SR&BIT2) //clear RX FIFO
elmicro 0:2290931492e7 101 if(LPC_SSP1->DR);
elmicro 0:2290931492e7 102 SSL0;
elmicro 0:2290931492e7 103 LPC_SSP1->DR = WRITE;
elmicro 0:2290931492e7 104 LPC_SSP1->DR = (iAddress >> 8) & 0xFF; //Send top address byte to read from
elmicro 0:2290931492e7 105 LPC_SSP1->DR = iAddress & 0xFF; //Send low address byte to read from
elmicro 0:2290931492e7 106 LPC_SSP1->DR = cByte;
elmicro 0:2290931492e7 107 while(LPC_SSP1->SR&BIT4); //wait for TX to end
elmicro 0:2290931492e7 108 while(LPC_SSP1->SR&BIT2) //clear RX FIFO
elmicro 0:2290931492e7 109 if(LPC_SSP1->DR);
elmicro 0:2290931492e7 110 SSL1;
elmicro 0:2290931492e7 111 }
elmicro 0:2290931492e7 112
elmicro 0:2290931492e7 113 /* ===================================================================
elmicro 0:2290931492e7 114 routine: FM25W_WriteBlock
elmicro 0:2290931492e7 115 purpose: Writes a block of data, starting at specified
elmicro 0:2290931492e7 116 memory address
elmicro 0:2290931492e7 117 parameters: <iAddress> First memory address to be written
elmicro 0:2290931492e7 118 <*ptrBlock> Pointer to data block to be written
elmicro 0:2290931492e7 119 <iCount> Length (in bytes) of data block
elmicro 0:2290931492e7 120 returns: nothing
elmicro 0:2290931492e7 121 date: 2012-04-05
elmicro 0:2290931492e7 122 author: Stefan Guenther
elmicro 0:2290931492e7 123 -------------------------------------------------------------------*/
elmicro 0:2290931492e7 124 void FM25W_WriteBlock(unsigned int iAddress, unsigned char *ptrBlock, unsigned int iCount)
elmicro 0:2290931492e7 125 {
elmicro 0:2290931492e7 126 int x;
elmicro 0:2290931492e7 127 while(!(LPC_SSP1->SR&BIT0)); //wait for TX FIFO to get empty
elmicro 0:2290931492e7 128 SSL0;
elmicro 0:2290931492e7 129 LPC_SSP1->DR = WREN; //unlock FRAM for writing
elmicro 0:2290931492e7 130 while(LPC_SSP1->SR&BIT4); //wait for TX to end
elmicro 0:2290931492e7 131 SSL1;
elmicro 0:2290931492e7 132 while(LPC_SSP1->SR&BIT2) //clear RX FIFO
elmicro 0:2290931492e7 133 if(LPC_SSP1->DR);
elmicro 0:2290931492e7 134 SSL0;
elmicro 0:2290931492e7 135 LPC_SSP1->DR = WRITE; //send write command
elmicro 0:2290931492e7 136 LPC_SSP1->DR = (iAddress >> 8) & 0xFF; //set start adress of block
elmicro 0:2290931492e7 137 LPC_SSP1->DR = iAddress & 0xFF;
elmicro 0:2290931492e7 138 for(x=0; x<iCount; x++)
elmicro 0:2290931492e7 139 {
elmicro 0:2290931492e7 140 while(!(LPC_SSP1->SR&BIT1)); //wait as TX FIFO is full
elmicro 0:2290931492e7 141
elmicro 0:2290931492e7 142 LPC_SSP1->DR = *ptrBlock;
elmicro 0:2290931492e7 143 ptrBlock++;
elmicro 0:2290931492e7 144 }
elmicro 0:2290931492e7 145 while(LPC_SSP1->SR&BIT4); //wait for TX to end
elmicro 0:2290931492e7 146 SSL1;
elmicro 0:2290931492e7 147 while(LPC_SSP1->SR&BIT2) //clear RX FIFO
elmicro 0:2290931492e7 148 if(LPC_SSP1->DR);
elmicro 0:2290931492e7 149 }
elmicro 0:2290931492e7 150
elmicro 0:2290931492e7 151 /* ===================================================================
elmicro 0:2290931492e7 152 routine: FM25W_ReadBlock
elmicro 0:2290931492e7 153 purpose: Reads a block of data, starting at specified
elmicro 0:2290931492e7 154 memory address
elmicro 0:2290931492e7 155 parameters: <iAddress> First memory address to be read
elmicro 0:2290931492e7 156 <*ptrBlock> Pointer to local RAM for data block
elmicro 0:2290931492e7 157 <iCount> Length (in bytes) of data block to read
elmicro 0:2290931492e7 158 returns: nothing
elmicro 0:2290931492e7 159 date: 2012-04-05
elmicro 0:2290931492e7 160 author: Stefan Guenther
elmicro 0:2290931492e7 161 -------------------------------------------------------------------*/
elmicro 0:2290931492e7 162 void FM25W_ReadBlock(unsigned int iAddress, unsigned char *ptrBlock, unsigned int iCount)
elmicro 0:2290931492e7 163 {
elmicro 0:2290931492e7 164 int x;
elmicro 0:2290931492e7 165
elmicro 0:2290931492e7 166 while(LPC_SSP1->SR&BIT2) //clear RX FIFO
elmicro 0:2290931492e7 167 if(LPC_SSP1->DR);
elmicro 0:2290931492e7 168 while(!(LPC_SSP1->SR&BIT0)); //wait for TX FIFO to get empty
elmicro 0:2290931492e7 169
elmicro 0:2290931492e7 170 SSL0;
elmicro 0:2290931492e7 171
elmicro 0:2290931492e7 172 LPC_SSP1->DR = READ;
elmicro 0:2290931492e7 173 LPC_SSP1->DR = (iAddress >> 8) & 0xFF; //send upper address byte to read from
elmicro 0:2290931492e7 174 LPC_SSP1->DR = iAddress & 0xFF; //send lower address byte to read from
elmicro 0:2290931492e7 175 while(LPC_SSP1->SR&BIT4); //wait for TX FIFO to get empty
elmicro 0:2290931492e7 176 x = LPC_SSP1->DR; //clear RX FIFO
elmicro 0:2290931492e7 177 x = LPC_SSP1->DR;
elmicro 0:2290931492e7 178 x = LPC_SSP1->DR;
elmicro 0:2290931492e7 179
elmicro 0:2290931492e7 180 for(x=0; x<iCount; x++)
elmicro 0:2290931492e7 181 {
elmicro 0:2290931492e7 182 LPC_SSP1->DR = 0; //send first dummy byte
elmicro 0:2290931492e7 183 while(LPC_SSP1->SR&BIT4); //wait for TX FIFO to get empty
elmicro 0:2290931492e7 184 *ptrBlock = LPC_SSP1->DR; //last FIFO entry is our data byte
elmicro 0:2290931492e7 185 ptrBlock++;
elmicro 0:2290931492e7 186 }
elmicro 0:2290931492e7 187 SSL1;
elmicro 0:2290931492e7 188 while(LPC_SSP1->SR&BIT2) //clear RX FIFO
elmicro 0:2290931492e7 189 if(LPC_SSP1->DR);
elmicro 0:2290931492e7 190 }
elmicro 0:2290931492e7 191